Project Investigators

Pavana Vennapusa, David White, Shauna Hallmark

Project Schedule

Jan 2014 to Sep 2017

Acknowledgments

Iowa Department of Transportation, Iowa Highway Research Board

Keywords

Project Description

Pavement foundation test sections at the Central Iowa Expo site (constructed in 2012 and paved in 2013) represents one of the most comprehensive studies of its kind in Iowa. Early research results demonstrate that the various pavement foundation systems provide significantly different support conditions (e.g., stiffness, drainage, durability, and uniformity). Further, the various material and treatments cover a wide range of material and construction costs. To more fully evaluate how to provide the best value pavement foundation system for Iowa roads, a performance monitoring program is needed. Past research have not specifically evaluated pavement foundation conditions with sufficient duration and testing frequency to properly characterize changes due to environmental conditions with time. This project site creates a unique opportunity to conduct in situ performance monitoring of the pavement system and foundation layers. The primary goals of this project are to conduct performance monitoring of the test sections and assess environmental impacts on the test sections for a 3-year period. Specific objectives are to assess the following: (a) Seasonal changes (within a year and over time) in foundation layer support conditions (strength and stiffness; (b) Seasonal changes (within a year and over time) in subbase layer permeability; (c) Seasonal temperature changes in foundation layers (document number of FIT cycles); (d) Seasonal changes in the in-ground stresses under loading; (e) Surface layer distresses over time (crack mapping and elevation changes); (f) Moisture changes in subbase and subgrade layers seasonally and over time; (g) Micro-mechanical changes in stabilized subgrade over time; (h) Seasonal water table changes; (i) Loss of supporVerosion,; and (j)Weather information monitoring.